title: Recurrence of bipolar mania is associated with catechol-O-methyltransferase Val(108/158)Met polymorphism.
abstract: BACKGROUND
  Catechol-O-methyltransferase (COMT) inactivates catecholamines, and a G-A transition in the COMT gene (rs4680) influences the enzyme activity and the interaction between cortical and subcortical dopaminergic neurotransmission. In patients affected by bipolar disorder rs4680 can influence antidepressant response and the propensity to develop psychotic symptoms, with the Met/Met genotype exerting a protective role. The same genotype could influence other dopamine-associated psychopathological features, such as mania.
  
  
  METHODS
  We genotyped rs4680 in a sample of 163 patients affected by bipolar disorder type I, and assessed the personal history of recurrence of the illness.
  
  
  RESULTS
  We observed a significant association between homozygosis for the rs4680 COMT low-activity variant and a reduced recurrence of manic, but not depressive, episodes during the course of the illness.
  
  
  CONCLUSIONS
  We suggest that rs4680 could be an inheritable aspect of the mechanisms of dopamine regulation that influence the individual susceptibility of patients with bipolar disorder to develop manic episodes of illness.
authors.affiliation: Royal Cornhill Hospital, Aberdeen, UK.
authors.forename: Francesco
authors.initials: F
authors.lastname: Benedetti
authors.forename: Sara
authors.initials: S
authors.lastname: Dallaspezia
authors.forename: Clara
authors.initials: C
authors.lastname: Locatelli
authors.forename: Daniele
authors.initials: D
authors.lastname: Radaelli
authors.forename: Sara
authors.initials: S
authors.lastname: Poletti
authors.forename: Cristina
authors.initials: C
authors.lastname: Lorenzi
authors.forename: Adele
authors.initials: A
authors.lastname: Pirovano
authors.forename: Cristina
authors.initials: C
authors.lastname: Colombo
authors.forename: Enrico
authors.initials: E
authors.lastname: Smeraldi
mesh_terms: D000328:Adult; D017668:Age of Onset; D000483:Alleles; D001714:Bipolar Disorder / Q000175:diagnosis / Q000235:genetics* / Q000503:physiopathology / Q000523:psychology; D002394:Catechol O-Methyltransferase / Q000235:genetics*; D004298:Dopamine / Q000378:metabolism; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D005838:Genotype; D006720:Homozygote; D006801:Humans; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic / Q000235:genetics*; D012008:Recurrence
chemical_list: D002394:Catechol O-Methyltransferase; D004298:Dopamine